code: def test_isinstance():
      def fun(x):
          assert ag_isinstance(x, tuple)
          assert ag_isinstance(x, ag_tuple)
          return x[0]
  
      fun((1.0, 2.0, 3.0))
      grad(fun)((1.0, 2.0, 3.0))
  
file_path: autograd/tests/test_tuple.py
imports: from __future__ import absolute_import
  from __future__ import print_function
  import autograd.numpy
  import autograd.numpy.random
  from autograd.test_util import check_grads
  from autograd import tuple, isinstance
  from autograd import grad
label_desc: Use image node_id 4 for calling a global function with example usage: test_isinstance() and returns: x